Centrifugal pumping means



Feb. 6, 1962 Filed March 5, 1959 FIG-1 E; A. STALKER CENTRIFUGAL PUMPING MEANS 2 Sheets-Sheet 1 INVENTOR.

EDWARD A. STALKER ATTORNEYS Feb. 6, 1962 E. A. STALKER 3,019,736

CENTRIFUGAL PUMPING MEANS Filed March 5, 1959 2 Sheets-Sheet 2 FIG-3 INVEN TOR.

EDWARD A. STALKER BY M M W ATTORNEYS finited States Patent Ofiilce 3,919,736 Patented Feb. 6, 1932 3,019,736 CENTRIFUGAL PUMPING MEANS Edward A. Stalker, Bay City, Mich. The Stalker Corp, 903 Woodside Drive, Essenville, Mich.) Filed Mar. 5, 1959, Ser. N 797,536 7 Claims. (Cl. 103-103) This invention relates to centrifugal pumping means such as compressors, and pumps.

A principal object of the invention is to provide a low cost rotor for use in centrifugal compressors and pumps.

Another object is to provide a strong composite rotor for relatively high rates of rotation in such compressors and pumps.

Still another object is to provide a strong and economical rotor for such machines formed of sheet metal parts bonded together.

Other objects will appear from the specification, appended claims and accompanying drawings in Which FiG. l is a fragmentary axial section through a centrifugal pumping means having a rotor constructed in accordance with the present invention;

FIG. 2 is a perspective view of an isolated rotor of FIG. 1;

FIG. 3 is a rear axial view of the rotor of PK 2;

FIG. 4 is a fragmentary section on line 44 of PEG. 1;

FIG. 5 is a side view of a blade for such a rotor; and FIG. 6 is an axial rear view of a fragment of such a rotor.

This invention discloses centrifugal rotors which are strong and economical to make even in small sizes. These are difficult to produce by current designs.

Economical construction is in part obtained by making the shroud in one piece rather than a plurality of segments, and the blades are bonded in place against the shroud extending radially outward therefrom. A strong attachment of the blades in the rotor is obtained by one or more tongues integral with the blades and extending radially inward through openings or slots in the shroud. The tongues fit closely to the sides of the disk and are bonded thereto by fused metal preferably by brazing. The inlet and exit ends of the blades have lugs Whose sides are bonded to the sides of slots, respectively, in the hub and shroud. Thus all the joints are shear joints with the fused metal subject to shear stress rather than tensile stress. hose joints are of the type which will secure the blades in the rotor safely even at high rates of rotation while resisting the vibration of the blades and the peripheral and radial stresses in the shroud and blades.

This present invention difiers from that shown in copending application Serial No. 744,941, filed June 27, 1958, in the use of the tongues and lugs and is especially significant for rotors without a shroud at the outer edges of the blades. It is difficult to make a composite rotor which can withstand the blade vibration and high centrifugal stresses in the absence of a blade tip shroud.

Referring to the drawings, the centrifugal rotor is indicated generally as It). It is housed in the case 12 and supported for rotation on bearing 14 carried on shaft 15.

The rotor comprises the blades 16, the unitary shroud 18 at the radially inner ends of the blades, and the radi ally extending disk 19. The blades and the shroud terminate at substantially the same radial distance from the axis of rotation.

Each blade is provided with one or more integral spaced tongues 21 and 22 extending radially inward through suitabel slots or openings 23, 24 respectively, in the shroud. The tongues fit closely to the side surfaces of the disk 19 and where two such tongues are used, they are in contact with opposite sides of the disk and all the tongues are brazed thereto. The blades are also brazed to the shroud 18 to form joints subject to stress in shear.

The front end of each blade has a lug 26 which is brazed in a slot 27 in the enlarged front end or hub 28 of the shaft 15. The lug 26 carries a large part of the centrifugal load of each blade by shear stress in the braze joining it to the shaft or hub. Part of this load is also carried by the shroud through the braze where the blade abuts the shroud. The major portion of the centrifugal load is carried by the disk 19 to which the tongues are brazed. The load is transferred from the tongues to the disk by shear stress which is the most reliable for a brazed joint.

Each blade at its tip end has the integral lug 36 which is bonded by fused metal to the radial surfaces of a slot 31 in the shroud. Adjacent the lugs 30 at their radially inward sides is a band of metal 32 bonded to the shroud 18 to reinforce the shroud against peripheral stresses, thus preventing the opposite surfaces of slots 31 from being displaced peripherally. Such a relative displacement would stress the fused metal of the joints and tend to cause cracks to appear therein.

The band 32 may be formed with a zig zag shape to define a labyrinth passage 33 with a correspondingly shaped part 34 of the case to serve as a seal, as shown in FlG. 1 and may also be machined as an integral part of the shroud. However for economy it is better fabricated separately and bonded to the shroud.

What is claimed is:

l. A composite rotor for a centrifugal pump adapted for operation in a case comprising a rotatable shaft, a radially extending disk mounted on said shaft, a unitary shroud having a plurality of openings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, each said blade having an integral tongue extending radially inward through a said opening in said shroud into contact with the side surface of said disk, and fused metal means bonding said tongues to said disk forming joints subject to stress in shear.

2. A composite rotor for a centrifugal pump adapted for operation in a case comprising a rotatable shaft, a radially extending disk mounted on said shaft, a unitary shroud having a plurality of openings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, each said blade having a pair of integral tongues extending radially inward through said openings in said shroud into contact with the opposite sides of said disk, and fused metal means bonding said tongues to said disk forming joints subject to stress in shear.

3. A composite rotor for a centrifugal pump adapted for operation in a case comprising a rotatable shaft forming a hub, a radially extending disk mounted on said shaft, a unitary shroud having a plurality of openings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, said blades having integral tongues extending radially inward through said openings in said shroud into contact with the side surface of said disk, fused metal means bonding said tongues to said disk, each said blade having a front end and a lug at its front end fixed in a corresponding slot in said hub.

4. A composite rotor for a centrifugal pump adapted for operation in a case comprising a rotatable shaft forming a hub, a radially extending disk mounted on said shaft, a unitary shroud having a plurality of openings therein, a plurality of blades mounted against said srroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, said blades having integral tongues extending radially inward through said openings in said shroud into contact with the side surface of said disk, fused metal means bonding said tongues to said disk, each said blade having a front end and a iug at its tip end fixed in a corresponding slot in said shroud.

5. A composite rotor for a centrifugal pump adapted for operation in a case comprising a rotatable shaft forming a hub, a radially extending disk mounted on said shaft, a unitary shroud having a plurality of openings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, said blades having radially outer tip ends and integral tongues extending radially inward through said openings in said shroud into contact with the side surface of said disk, fused metal means bonding said tongues to said disk, and a band fixed to the radially inward side of said shroud adjacent said tip ends of said blades for reinforcing said shroud against peripheral displacement.

6. ln a centrifugal pump, the combination of a case, a rotatable shaft journaled in said case forming a hub, a radially extending disk mounted on said shaft, a unitary shroud within said case having a plurality of openings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, said blades having radially outer tip ends and integral tongues extending radially inward through said openings in said shroud into contact with the side surface of said disk, fused metal means bonding said tongues to said disk, and a band fixed to the radially inward side of said shroud adjacent said tip ends of said blades and having sealing engagement with the adjacent Wall of said case.

7. In a centrifugal pump, the combination of a case, a rotatable shaft journaled in said case forming a hub, a radially extending disk mounted on said shaft, a unitary shroudwithin said case having a plurality of open ings therein, a plurality of blades mounted against said shroud and bonded thereto by fused metal, said blades and said shroud terminating at substantially the same radial distance from the axis of rotation, said blades having radially outer tip ends and integral tongues extending radially inward through said openings in said shroud into contact with the side surface of said disk, fused metal means bonding said tongues to said disk, and a band fixed to the radially inward side of said shroud adjacent said tip ends of said blades and having sealing engage ment with the adjacent wall of said case, said band and said wall having interfitting parts forming a labyrinth sealing passage therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 926,442 Smoot June 29, 1909 2,031,521 Baumann et a1. Feb. 18, 1936 2,457,325 Sidell Dec. 28, 1948 2,865,598 Maseson Dec. 23, 1958 FOREIGN PATENTS 118,988 Sweden June 10, 1957 157,047 Australia June 15, 1954 159,785 Great Britain Mar. 10, 1921 

